I know you're mostly all big wusses really
That may or may not be true but you took a risk confronting this guy like you did. Most drunken idiots may be harmless but you don't ever know how they will react. I have no idea who Jo Frost actually is but if he/she advises confronting drunken football fans they he/she is wrong. If I'd been in a immigration hall when such an incident took place I would have gone straight to the nearest booth and told the guy that some idiot was threatening a woman and two children. The Police would have attended within 30 seconds.
The police are paid to deal with such situations and they can do it a lot better than a fare paying passenger. Also, an experience with two police officers carrying machine guns accompanied by a large German Shepherd would probably be an interesting learning experience for the thug in question.